Updated devonfw-ide instances installed prior to 2020.04 are not detected

[maybeec]

Describe the bug
Updated devonfw-ide instances installed prior to 2020.04 are not detected.
Even one advantage of devonfw ide is, that we can move it folderwise to another machine (in case you want to move to a new laptop). Therefore the .devon folder might be lost.
Same case if you rename your installation folder once.

Therefore, we need to find a different option to detect instances or we have to make devonfw ide more stable in maintaining the paths registered in this file.

Expected behavior
devonfw ides should be always detected. On move / On update etc.